This invention relates to improvements to a top head drive assembly for an earth drilling machine such as a machine for drilling oil or water wells.
High speed, automatic operation is becoming increasingly important for a wide range of earth drilling machines. High speed operation reduces the drilling time and automatic operation reduces the number of drillers required at the drilling site. Both of these factors substantially reduce drilling costs, and automatic operation provides the added advantage of reduced injury to drillers.
Another important factor in drilling machines is that significant advantages can be obtained by minimizing the overall height of the drilling machine and in particular the drilling mast. By reducing the height of the drilling machine, the weight of the drilling machine and its susceptibility to wind loading problems are both reduced. These factors can result in important savings in the size and cost of the drilling machine, along with important advantages in terms of increased mobility, lower moving costs and faster rig-up and rig-down times.
It is an object of the present invention to provide an improved top head drive assembly and components for a top head drive assembly which minimize the height of the top head drive assembly and which cooperate to facilitate high speed, remote controlled automatic drilling operations.